1. Field of the invention
This present invention relates to a device and method thereof for enhancing the resolution of a digital encoder.
2. Description of the prior art
In the prior art, the digital encoder coordinates the corresponding code strip of the resolution or coder wheel of the resolution to produce the output waveform of the digital signal.
Please refer to FIG. 1. FIG. 1 is a schematic diagram the output waveform 8 of the digital signal produced by the corresponding encoder strip 6 in the prior art. There are plural sets of alternating black and white patterns on the encoder strip 6 of the prior art. The area with diagonal lines on the encoder strip 6 of FIG. 1 is a black area 7. The encoder strip 6 is a detecting element of light to detect the style of alternating black and white pattern on the encoder strip 6; moreover, the digital encoder produces the corresponding output of the digital signal. When the detecting element detects the black area 7, the digital encoder outputs the low level waveform; in contrast, when the detecting element detects the white area, the digital encoder outputs the high level waveform. The output waveform of the digital encoder is used to control the moving position and velocity of the motor.
In the prior art, the operation of the motor is controlled by digital signals and analog signals. The purpose is to achieve the exact operation of controlling the motor by controlling the resolution of the digital signal and analog signal. Because a digital signal is not a continual signal, the resolution is lower; therefore, the digital signal is used to control the rotation of the motor in positions of bigger scale. Because an analog signal is a continual signal, the resolution is higher. Thus, the analog signal is used to control the rotation of the motor in positions of smaller scale. Through operating digital signals and analog signals together, the prior art can precisely control the operation of the motor. This operating style of using digital signals and the analog signals together in the prior art can be achieved by a special control chip.
The main objective of the present invention is to enhance the resolution of the digital signal and uses only the digital signal to achieve the purpose of precisely controlling the rotational operation of the motor.